i965: Add SIMD8 URB write low-level IR instruction

This is all we need from the generator for SIMD8 vertex shaders.  This
opcode is just the send instruction, all the hard work will happen
in the visitor using LOAD_PAYLOAD.

Signed-off-by: Kristian Høgsberg <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

6 files changed, 51 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
index d4211496168..843ef32cbbd 100644
--- a/src/mesa/drivers/dri/i965/brw_defines.h
+++ b/src/mesa/drivers/dri/i965/brw_defines.h
@@ -908,6 +908,8 @@ enum opcode {
    SHADER_OPCODE_GEN4_SCRATCH_WRITE,
    SHADER_OPCODE_GEN7_SCRATCH_READ,
 
+   SHADER_OPCODE_URB_WRITE_SIMD8,
+
    VEC4_OPCODE_PACK_BYTES,
    VEC4_OPCODE_UNPACK_UNIFORM,
 
@@ -1529,6 +1531,7 @@ enum brw_message_target {
 
 #define BRW_URB_OPCODE_WRITE_HWORD  0
 #define BRW_URB_OPCODE_WRITE_OWORD  1
+#define GEN8_URB_OPCODE_SIMD8_WRITE  7
 
 #define BRW_URB_SWIZZLE_NONE          0
 #define BRW_URB_SWIZZLE_INTERLEAVE    1
diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index a0fb5653998..9365b7a29b9 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -509,6 +509,7 @@ fs_inst::is_send_from_grf() const
    case FS_OPCODE_INTERPOLATE_AT_PER_SLOT_OFFSET:
    case SHADER_OPCODE_UNTYPED_ATOMIC:
    case SHADER_OPCODE_UNTYPED_SURFACE_READ:
+   case SHADER_OPCODE_URB_WRITE_SIMD8:
       return true;
    case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
       return src[1].file == GRF;
@@ -898,6 +899,8 @@ fs_inst::regs_read(fs_visitor *v, int arg) const
       return mlen;
    } else if (opcode == FS_OPCODE_FB_WRITE && arg == 0) {
       return mlen;
+   } else if (opcode == SHADER_OPCODE_URB_WRITE_SIMD8 && arg == 0) {
+      return mlen;
    } else if (opcode == SHADER_OPCODE_UNTYPED_ATOMIC && arg == 0) {
       return mlen;
    } else if (opcode == SHADER_OPCODE_UNTYPED_SURFACE_READ && arg == 0) {
@@ -992,6 +995,7 @@ fs_visitor::implied_mrf_writes(fs_inst *inst)
       return 2;
    case SHADER_OPCODE_UNTYPED_ATOMIC:
    case SHADER_OPCODE_UNTYPED_SURFACE_READ:
+   case SHADER_OPCODE_URB_WRITE_SIMD8:
    case FS_OPCODE_INTERPOLATE_AT_CENTROID:
    case FS_OPCODE_INTERPOLATE_AT_SAMPLE:
    case FS_OPCODE_INTERPOLATE_AT_SHARED_OFFSET:
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index f0e6f251dbb..d252caf9b68 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -705,6 +705,7 @@ private:
                       struct brw_reg implied_header,
                       GLuint nr);
    void generate_fb_write(fs_inst *inst, struct brw_reg payload);
+   void generate_urb_write(fs_inst *inst, struct brw_reg payload);
    void generate_blorp_fb_write(fs_inst *inst);
    void generate_pixel_xy(struct brw_reg dst, bool is_x);
    void generate_linterp(fs_inst *inst, struct brw_reg dst,
diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
index 95bdfc1b6aa..c131db2391c 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
@@ -336,6 +336,27 @@ fs_generator::generate_fb_write(fs_inst *inst, struct brw_reg payload)
 }
 
 void
+fs_generator::generate_urb_write(fs_inst *inst, struct brw_reg payload)
+{
+   brw_inst *insn;
+
+   insn = brw_next_insn(p, BRW_OPCODE_SEND);
+
+   brw_set_dest(p, insn, brw_null_reg());
+   brw_set_src0(p, insn, payload);
+   brw_set_src1(p, insn, brw_imm_d(0));
+
+   brw_inst_set_sfid(brw, insn, BRW_SFID_URB);
+   brw_inst_set_urb_opcode(brw, insn, GEN8_URB_OPCODE_SIMD8_WRITE);
+
+   brw_inst_set_mlen(brw, insn, inst->mlen);
+   brw_inst_set_rlen(brw, insn, 0);
+   brw_inst_set_eot(brw, insn, inst->eot);
+   brw_inst_set_header_present(brw, insn, true);
+   brw_inst_set_urb_global_offset(brw, insn, inst->offset);
+}
+
+void
 fs_generator::generate_blorp_fb_write(fs_inst *inst)
 {
    brw_fb_WRITE(p,
@@ -1887,6 +1908,10 @@ fs_generator::generate_code(const cfg_t *cfg, int dispatch_width)
 	 generate_scratch_read_gen7(inst, dst);
 	 break;
 
+      case SHADER_OPCODE_URB_WRITE_SIMD8:
+	 generate_urb_write(inst, src[0]);
+	 break;
+
       case FS_OPCODE_UNIFORM_PULL_CONSTANT_LOAD:
 	 generate_uniform_pull_constant_load(inst, dst, src[0], src[1]);
 	 break;
diff --git a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
index 0813f645728..eba2fdd0816 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_reg_allocate.cpp
@@ -385,6 +385,7 @@ fs_visitor::setup_payload_interference(struct ra_graph *g,
 
       /* Special case instructions which have extra implied registers used. */
       switch (inst->opcode) {
+      case SHADER_OPCODE_URB_WRITE_SIMD8:
       case FS_OPCODE_FB_WRITE:
          /* We could omit this for the !inst->header_present case, except that
           * the simulator apparently incorrectly reads from g0/g1 instead of
@@ -522,6 +523,19 @@ fs_visitor::setup_mrf_hack_interference(struct ra_graph *g, int first_mrf_node)
    }
 }
 
+static bool
+is_last_send(fs_inst *inst)
+{
+   switch (inst->opcode) {
+   case SHADER_OPCODE_URB_WRITE_SIMD8:
+   case FS_OPCODE_FB_WRITE:
+      return inst->eot;
+   default:
+      assert(!inst->eot);
+      return false;
+   }
+}
+
 bool
 fs_visitor::assign_regs(bool allow_spilling)
 {
@@ -594,7 +608,7 @@ fs_visitor::assign_regs(bool allow_spilling)
           * We could just do "something high".  Instead, we just pick the
           * highest register that works.
           */
-         if (inst->opcode == FS_OPCODE_FB_WRITE && inst->eot) {
+         if (is_last_send(inst)) {
             int size = virtual_grf_sizes[inst->src[0].reg];
             int reg = screen->wm_reg_sets[rsi].class_to_ra_reg_range[size] - 1;
             ra_set_node_reg(g, inst->src[0].reg, reg);
diff --git a/src/mesa/drivers/dri/i965/brw_shader.cpp b/src/mesa/drivers/dri/i965/brw_shader.cpp
index 56aa7578603..b3b1ad79d62 100644
--- a/src/mesa/drivers/dri/i965/brw_shader.cpp
+++ b/src/mesa/drivers/dri/i965/brw_shader.cpp
@@ -453,6 +453,8 @@ brw_instruction_name(enum opcode op)
       return "gen4_scratch_write";
    case SHADER_OPCODE_GEN7_SCRATCH_READ:
       return "gen7_scratch_read";
+   case SHADER_OPCODE_URB_WRITE_SIMD8:
+      return "gen8_urb_write_simd8";
 
    case VEC4_OPCODE_PACK_BYTES:
       return "pack_bytes";
@@ -754,6 +756,7 @@ backend_instruction::has_side_effects() const
 {
    switch (opcode) {
    case SHADER_OPCODE_UNTYPED_ATOMIC:
+   case SHADER_OPCODE_URB_WRITE_SIMD8:
    case FS_OPCODE_FB_WRITE:
       return true;
    default: